PHP: uasort() function
PHP: Maintaining index association, sort an array with a user-defined comparison function
The uasort() function is used to sort an array by its values using a user-defined comparison function.
The function maintains the existing key index.
Version:
(PHP 4 and above)
Syntax:
uasort(array_name, user_defined_function)
Parameters:
Name | Description | Required / Optional |
Type |
---|---|---|---|
array_name | The specified array which will be sorted. | Required | Array |
user_defined_function | User supplied function. | Required | - |
Return value:
TRUE on success or FALSE on failure.
Value Type: Boolean.
Example :
<?php
function my_sort($x, $y)
{
if ($x == $y) return 0;
return ($x > $y) ? -1 : 1;
}
$people = array("10" => "javascript",
"20" => "php", "60" => "vbscript",
"40" => "jsp");
uasort($people, "my_sort");
print_r ($people);
?>
Output:
Array ( [60] => vbscript [20] => php [40] => jsp [10] => javascript )
Pictorial Presentation:

View the example in the browser
Practice here online :
See also
PHP: Tips of the Day
Filters the collection using the given callback
Example:
<?php function tips_reject($items, $func) { return array_values(array_diff($items, array_filter($items, $func))); } print_r(tips_reject(['Apple', 'Pear', 'Kiwi', 'Banana'], function ($item) { return strlen($item) > 4; })); ?>
Output:
Array ( [0] => Pear [1] => Kiwi )
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